ISSN:
1573-7357
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Physik
Notizen:
Abstract The crystal structure of Sr 2 Y 0.8 Ca 0.2 Co 2 O 6 is orthorhombic below 270 K (Immm, a = 3.84029(7) Å, b = 3.80691(6) Å and c = 19.4980(3) Å at 20 K), transformed from tetragonal (I4/mmm, a = 3.82765(6) Å and c = 19.5795(3) Å) at 295 K. The crystal structure distortion is accompanied by an anomalous temperature dependence of the degree of buckling of the CoO 2 plane and is correlated with the development of anisotropic antiferromagnetic ordering of magnetic moments (2.93(2) μ B per Co at 20 K). A magnetically glassy state below about 35 K and variable range hopping conduction below about 64 K for $$\begin{gathered} Sr_2 Y_{1 - x} Ca_x Co^{3.4 + } _2 O_{7 - z} (0.2 \leqslant x \leqslant 0.5,0.21 \leqslant z \leqslant 0.38) \hfill \\ \hfill \\ \end{gathered} $$ were found by magnetic susceptibility and electrical resistivity measurements.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1022534420416
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